The primary purpose of these categories is to facilitate manual or automated checking of text in other languages.

This category should only be added with the {{Lang}} family of templates, never explicitly.

For example: {{Lang|wlm|text in Middle Welsh language here}}, which wraps the text with <span lang="wlm">. Also available is {{Lang-wlm|text in Middle Welsh language here}} which displays as Middle Welsh: text in Middle Welsh language here.